After emerging from nests, neonate sea turtles entering the water are thought to orientate away from shore using wave cues to guide them out to sea. Artificial light may interfere with this process, but the relative importance of natural and anthropogenic cues to the dispersal of hatchlings is unknown. Here, we used acoustic telemetry to track the movement of flatback turtle (Natator depressus) hatchlings dispersing through nearshore waters. Turtles dispersed in the presence and absence of artificial light through a receiver array where a range of oceanographic variables were measured. Turtle tracks were analysed using a full subsets Generalised Additive Mixed Model approach to identify the most important cues influencing the bearing, variance in bearing (a measure of the ability to orientate directly), rate of travel and time spent in the array. Artificial light reduced their swim speed by up to 30%, increased the amount of time spent in nearshore waters (by 50–150%) and increased the variance in bearing (100–180% more variable), regardless of oceanographic conditions. Under ambient conditions, ocean currents affected the bearing of hatchlings as they left the shore, but when light was present, this effect was diminished, showing turtles actively swam against currents in their attempts to move towards light. After accounting for the effects of currents on hatchlings dispersing under ambient conditions, turtles swam offshore by moving perpendicular to the coastline and did not appear to orient into incident wave direction. Overall, light disrupted the dispersal of hatchlings causing them to linger, become disoriented in the near shore and expend energy swimming against ocean currents.

Quilombos are settlements originally founded by Africans and African descendants (Quilombolas) in remote parts of Brazil to escape slavery. Due to individual histories, Quilombos nowadays exhibit different states of industrialisation, making them ideal for studying the influence of electrification on daily behaviour. In a comparative approach, we aimed to understand whether and how human sleep changes with the introduction of artificial light. We investigated daily rest-activity-rhythms and sleep-patterns in the Quilombolas' by both wrist actimetry and the Munich ChronoType Questionnaire (MCTQ; the results of these two instruments correlated highly). Seven communities (MCTQ: N = 213/actimetry: N = 125) were compared in this study. Light exposure, phase of activity, sleep timing and duration differ across communities with various levels of urbanisation and histories of access to electricity. People living without electricity and those, who acquired it only very recently on average sleep earlier than those in more urbanised communities (mid-sleep about 1 hour earlier); sleep duration tends to be longer. Our results and those of others show that use of electricity and modern lifestyles have changed sleep behaviour. To understand the consequences of these changes for health, further studies are warranted.

Light pollution is ranked high among recent forms of environmental degradation. While there have been many studies focusing on the diverse effects of artificial lighting on human health, wild life, etc., studies related to the social-economic impact of light pollution have been neglected. In the current paper, we assessed the relationship between economic development and light pollution. Using collected field data of illuminance levels as a measure of light pollution and land prices as an indicator of economic development, we drew conclusions about the effects of economic development on light pollution. The results did not show an inverted-U relationship between the two variables, hence denouncing the Environmental Kuznets Curve (EKC) theory. A regression analysis test showed an R-squared value of 0.322 at p > 0.215. Looking at the obtained results, which show no statistical significance between the two variables, we advise that local light pollution regulation laws and policies be equally stringent throughout districts/cities, regardless of economic status.

The brighter nights have posed new challenges to the wild species by affecting their temporal physiology. The present study on Indian weaver bird (Ploceus philippinus) investigated if exposure to bright light at different phases of night affects their clock-mediated daily functions. Birds were placed individually in specially designed activity cages under short days and long nights (8L:16D; L = 100 lux, D < 0.1 lux) for approximately 3 weeks (19 days). Thereafter, they were divided into four groups (n = 6-9), and given approximately 2 lux light either for the entire night (ZT 08-24; zeitgeber time 0 = time of light on; pattern A) or for 4 hr (pattern B), placed in 16 hr night such that its onset coincides with the onset of night (early night group, ZT 08-12), its end with the end of night (late night group, ZT 20-24), or the night was interrupted in the middle (midnight group, ZT 14-18). The results showed that bright light in entire night induced early onset of day activity and fragmented rest at night, however, if given at different phases of night, it made the days longer by delaying end (early night group) or advancing onset of daily activity (late night group). It also suppressed the melatonin levels and increased body temperature. These results suggest that bright light at night alters the perception of daylength and affects the underlying physiology. The findings may be useful in adopting a strategy for use of night light without disturbing species fitness in their environment.

This article explores the relationship between the Enlightenment as a cultural and intellectual phenomenon and actual illumination in the long 18th century. Focused on street lighting in Paris, it nonetheless seeks to situate the French case in the broader context of developments in public lighting in the French provinces, Europe, and the Atlantic World. In the concerted effort to illuminate dark streets, the Enlightenment was operationalized in ways that bore fundamentally on commerce, sociability, and perceptions of progress, enlightened government, and enlightened space. At the same time, the attempt to illuminate formerly dark spaces generated reactions. A ‘dialectic of illumination’ was the counterpart to the dialectic of Enlightenment, fostering resistance to the new regime of light and its efforts to impose, through human ingenuity and instrumental reason, greater security and social control.